Vacuum Casting speed/pressure

[katkramer]

I have the KayaCast, and have been using it with my Formlabs casting.

I’ve had it since maybe 2015, and it’s a great system. I like that it can take both solid and perforated flasks, so that flexibility is really nice. One drawback…when I bought mine, it came with a single perforated flask, and the necessary adapter for the drop-in chamber. I found other perforated flasks online, and just assumed that they would fit…THEY DID NOT.

I learned this when I had a large run burning out in the kiln. Fortunately, I had worked with a local metal shop that has a water jet cutter, and they were able to quickly cut a couple of steel plates with the right sized holes. If you decide to get a KayaCast and need those CAD files, I’m more than happy to share them. I used a fiberglas-reinforced baking mat to make the gasket. The metal adapter doesn’t have to even been precise…there is a little wiggle room, so even if it were cut with a regular cutting torch, it should work.

For me, it was the right price…a larger automatic system wasn’t in my budget because I only do single pieces or limited runs. On my larger runs, I think I’ve been able to cast 60 charms or so in one flask? I’m using Neutec sprues/bases with the perforated flasks. Just make sure that the flasks fit…check to see what larger perforated flask is included…that diameter is what you’ll want to stick to.

I took a class from Kate Wolf (wax carving goddess…her tools work GREAT on resin), and I asked her if she preferred a centrifugal setup or vacuum. She said vacuum. You’ll have to experiment to get the metal temperatures right, but it will depend more on your flask temperature when it comes out of the kiln and metal temperature if you’re doing fine work. My biggest issues have been what I believe to be incomplete ash burnout, but I’ve seen some folks using a vacuum on the flasks, returning them to the kiln so they can come back up to casting temperature. That residue can cause “crustiness” on the surface of your pieces. You’ll also want to add boric acid to your investment to strengthen it.

There are versions that have the vacuum table only, but the one I think you’re considering has the drop-in vacuum as well…I recommend that version.

What quantity will you be casting?

[raylpz88]

@katkramer thank you for your replay, it is very helpfull and very clear. It is good to know that kaya cast is good enough, because I might not find other than that in my country. Thanks for offering me th CAD, but i will try to find it around my county first.
I am not sure yet about my quantity, may be about 20 to 50 per month.
What kind of metal are working on? I am working with 18k gold
Have you figur out how to get rid the incomplete ash burnout?

[katkramer]

Sorry for the delayed reply! I’ve been out of touch for awhile, dealing with family issues.

The KayaCast would be good for your quantity…but it depends on your budget. If you’re doing 18K gold, and have that volume, you might be better with a more automated system. But this is definitely a lesser-priced option that would work.

Incomplete ash burnout is still hit or miss with me. I was going to try one of the solutions with the aquarium pump to add oxygen. I also noticed that there is a system online that helps circulate air through the chamber…it might have been from Paragon? I know I referenced it in an earlier post on the forum.

Right now, I’m using compressed, canned air to gently blow into the cavity, or just blow into the cavity with my breath…then place it back into the kiln for the final twenty minutes. I’ve had better results with Castable v2 than Castable Wax, but I need to do a little more experimentation. I haven’t cast in awhile, and have been focusing more on creating an online ZBrush course. I need to get back to casting.

Did you ever get a casting setup?